The World’s Biggest Oil Companies

Different criterions give you different rankings of the oil companies. Usually in this industry, the production and the reserve are the most useful factors to assess the companies. It is really difficult to tell the reserve a state-owned oil company have, usually which is regarded as top secret, sometimes even the oil company publicized its reserve but the figure was still not convincing1. In this following 2012 ranking of the world’s biggest is based on the combined volumes of oil and natural gas that these companies produce each day, which allows the comparison of private sector and state-owned oil companies.2, 3.